1. Field of the Invention
The present invention relates to a method of processing documents, more specifically, to a method of conveying documents for an automatic document feeder.
2. The Related Art
Please refer to FIG. 20 to FIG. 41, they show a conventional method of conveying document for an automatic document feeder (ADF). The ADF 800 includes a case 802, a conveying path 804, an inverting path 806, a feeding tray 808, a picking up roller 810, a separating roller 812, a plurality of conveying rollers 814, a scanning section 816, a discharging roller 818 and a discharging tray 820.
The conveying path 804 defined in the case 802 includes an upstream feeding section 822 and a downstream discharging section 824 respectively connected to the outside of the case 802. The inverting path 806 defined in the case 802 branches from the downstream discharging section 824 and merges to a position of the conveying path 804 where arranged a downstream position relative to the separating roller 812 and a upstream position relative to the scanning section 816. Therefore, the inverting path 806 and a portion of the conveying path 804 are together formed of a loop.
The feeding tray 808 is positioned at the outside of the case 802 and adjacent to the upstream feeding section 822 for being stacked a bundle of documents P1, P2. The picking up roller 810 is positioned in the case 802 and at the upstream feeding section 822 for picking up the documents P1, P2 from the feeding tray 808 and conveying the documents P1, P2 into the conveying path 804.
The separating roller 812 is positioned at the upstream feeding section 822 and at a downstream position relative to the picking up roller 810. The separating roller 812 includes an active separating roller 826 and a driven separating roller 828 for separating the documents P1, P2 and conveying the documents P1, P2 one by one to the scanning section 816. Especially, the driven separating roller 828 can be replaced by a separating pad (not shown in figures).
The conveying rollers 814 are distributed along the conveying path 804 and the inverting path 806 for conveying the documents P1, P2 from the upstream feeding section 822, through the scanning section 816, to the downstream discharging section 824. The scanning section 816 is positioned between the upstream feeding section 822 and the downstream discharging section 824 for scanning the documents P1, P2.
The discharging roller 818 is positioned at the downstream discharging section 824 for discharging the documents P1, P2 from the conveying path 804. The discharging tray 820 is positioned at the outside of the case 802 and adjacent to the downstream discharging section 824 for stacking the scanned documents P1, P2. Especially, the discharging tray 820 is positioned below the feeding tray 808.
The conventional method of conveying documents P1, P2 for the ADF 800 includes the following steps:    Step 902: Stacking the documents P1, P2 on the feeding tray 808 (shown in FIG. 20);    Step 904: Picking up the document P1 from the feeding tray 808 by the picking up roller 810 and conveying the document P1 into the conveying path 804 by the separating roller 812 positioned at the upstream feeding section 822 (shown in FIG. 21);    Step 906: Conveying the document P1 from the upstream feeding section 822 and passing through the scanning section 816 by the conveying rollers 814 for scanning a front surface of the document P1 (shown in FIG. 22);    Step 908: Conveying the document P1 from the scanning section 816 to the discharging roller 818 positioned at the downstream discharging section 824 by the conveying rollers 814, and then discharging the document P1 from the downstream discharging section 824 to arrange a leading end of the document P1 (arrow of document P1 in FIG. 23) at the outside of the case 802 by the clockwise rotation of the discharging roller 818, and then clipping a trailing end of the document P1 by stopping rotating of the discharging roller 818 (shown in FIG. 23);    Step 910: Conveying the document P1 into the downstream discharging section 824 by the counterclockwise rotation of the discharging roller 818 (shown in FIG. 24);    Step 912: Conveying the document P1 into the inverting path 806 for inverting the document P1 to arrange the leading thereof to become the trailing end (the trailing end of the document P1 becomes leading end shown as arrow in FIG. 25), and the front surface become a rear surface (shown in FIG. 25);    Step 914: Conveying the document P1 into the conveying path 804 and passing through the scanning section 816 again for scanning the rear surface of the document P1 (shown in FIG. 26);    Step 916: Conveying the document P1 from the scanning section 816 to the downstream discharging section 824 by the conveying rollers 814, and then discharging the leading end of the document P1 at the outside the case 802 by the clockwise rotation of the discharging roller 818, meanwhile, picking up the document P2 and conveying the document P2 into the upstream feeding section 822 by the picking up roller 810, and then clipping the document P2 to retain the document P2 in the upstream feeding section 822 by the separating roller 812 (shown in FIG. 27);    Step 918: Clipping the trailing end of the document P1 by stopping the rotation of the discharging roller 818, and then conveying the document P1 into the inverting path 806 for inverting the document P1 to arrange the leading end thereof to become the trailing end, and the front surface to become the rear surface again, meanwhile, keeping clipping the document P2 to retain the document P2 in the upstream feeding section 822 by the separating roller 812 (shown in FIG. 28);    Step 920: Conveying the document P1 into the conveying path 804 through the inverting path 806 again and passing through the scanning section 816, meanwhile, performing a non-scanning process of the front surface of the document P1, and conveying the document P2 to the scanning section 816 after the trailing end of the document P1 is conveyed to depart from the inverting path 806 by the conveying rollers 814 (shown in FIG. 29);    Step 922: Conveying the document P1 from the scanning section 816 to the discharging roller 818 positioned in the downstream discharging section 824 by the conveying rollers 814, meanwhile, conveying the document P2 from the upstream feeding section 822 to the scanning section 816 (shown in FIG. 30);    Step 924: Discharging the document P1 from the downstream discharging section 824 of the conveying path 804 by the discharging roller 818, meanwhile, conveying the document P2 to pass through the scanning section 816 for scanning a front surface of the document P2 (shown in FIG. 31);    Step 926: Discharging the document P1 from the case 802 to be putted on the discharging tray 820, meanwhile, conveying the document P2 from the scanning section 816 to the downstream discharging section 824 by the conveying rollers 814, and then discharging a leading end of the document P2 at the outside the case 802 by the clockwise rotation of the discharging roller 818, and then clipping a trailing end of the document P2 by stopping rotating of the discharging roller 818 (shown in FIG. 32);    Step 928: Conveying the document P2 into the downstream discharging section 824 by the counterclockwise rotation of the discharging roller 818 (shown in FIG. 33);    Step 930: Conveying the document P2 into the inverting path 806 for inverting the document P2 to arrange the leading thereof to become the trailing end, and the front surface to become a rear surface (shown in FIG. 34);    Step 932: Conveying the document P2 into the conveying path 804 and passing through the scanning section 816 again for scanning the rear surface of the document P2 (shown in FIG. 35);    Step 934: Conveying the document P2 from the scanning section 816 to the downstream discharging section 824 by the conveying rollers 814, and then discharging the leading end of the document P2 at the outside the case 802 by the clockwise rotation of the discharging roller 818, meanwhile, picking up a next document P3 and conveying the document P3 into the upstream feeding section 822 by the picking up roller 810, and then clipping the document P3 to retain the document P3 in the upstream feeding section 822 by the separating roller 812 (shown in FIG. 36);    Step 936: Clipping the trailing end of the document P2 by stopping the rotation of the discharging roller 818, and then conveying the document P2 into the inverting path 806 for inverting the document P2 to arrange the leading thereof to become the trailing end, and the front surface to become the rear surface again, meanwhile, keeping clipping the document P3 to retain the document P3 in the upstream feeding section 822 by the separating roller 812 (shown in FIG. 37);    Step 938: Conveying the document P2 into the conveying path 804 through the inverting path 806 again and passing through the scanning section 816, meanwhile, performing a non-scanning process of the front surface of the document P2, meanwhile, conveying the document P3 from the upstream feeding section 822 to the scanning section 816 after the trailing end of the document P2 is conveyed to depart from the inverting path 806 by the conveying rollers 814 (shown in FIG. 38);    Step 940: Conveying the document P2 from the scanning section 816 to the discharging roller 818 positioned in the downstream discharging section 824 by the conveying rollers 814, meanwhile, keeping conveying the document P3 from the upstream feeding section 822 to the scanning section 816 (shown in FIG. 39);    Step 942: Discharging the document P2 from the downstream discharging section 824 of the conveying path 804 by the discharging roller 818, meanwhile, conveying the document P3 to pass through the scanning section 816 for scanning a front surface of the document P3 (shown in FIG. 40); and    Step 944: Discharging the document P2 from the case 802 of the ADF 800 to be putted on the discharging tray 820, meanwhile, conveying the document P3 from the scanning section 816 to the downstream discharging section 824 by the conveying rollers 814, and then discharging a leading end of the document P3 at the outside the case 802 by the clockwise rotation of the discharging roller 818, and then clipping a trailing end of the document P3 by stopping rotating of the discharging roller 818 (shown in FIG. 41).
Therefore, procedure of the document P3 and a next document P4 is similar as above steps. As described above, the documents P1, P2 are performed three times the conveying procedures to be conveyed to pass through the scanning section 814 and performed two times the inverting procedures to be conveyed through the inverting path 806 for arranging the orientation of the scanned documents P1, P2 on the discharging tray 820 to be same with the orientation of the non-scanned documents P1, P2 on the feeding tray 808.
However, a next document (document P2) is waited in the upstream feeding section 822, when a preceding document (document P1) is performed with the first conveying procedure, the first inverting procedure, the second conveying procedure and the second converting procedure. It is inefficient and wastes long time for waiting the two times the conveying procedures and two times the inverting procedures of the preceding document.